Hurricane Isaac, packing sustained winds of 80 mph, made landfall in the midst of coastal wetlands in Plaquemines Parish just southwest of the mouth of the Mississippi River on Tuesday at 6:45 p.m.

View full sizeNational Weather ServiceThe circular eye of Hurricane Isaac is visible just west of the mouth of the Mississippi River on the Doppler radar of the Slidell office of National Weather Service.

At 7 p.m., the center of Isaac was estimated by NOAA Doppler radar to be about 10 miles southwest of the river's mouth and about 90 miles southeast of New Orleans.

A sustained wind of 45 mph and a gust to 62 mph was observed within the past hour at Lakefront Airport in New Orleans. A wind gust of 56 mph was reported at Galliano, according to the National Hurricane Center.

On the storm's east side, a National Ocean Service gauge measured a storm surge of 8.8 feet at Shell Beach in St. Bernard Parish.

Isaac is moving northwest at 8 mph. Hurricane force winds extend outward up to 60 miles from the storm's center, mainly to the northeast and east. Tropical storm-force winds extend outward up to 185 miles.

Forecasters warn that as Isaac moves towards populated areas, people should remember that its winds are significantly stronger at higher levels, which could especially affect upper floors of high-rise buildings. At the 30th floor, the winds are likely to be one Saffir-Simpson hurricane category stronger than at the surface.

A wind gust of 106 mph was recently reported at an elevation of 279 feet, the equivalent of the 28th floor, on an oil rig off the southeast Louisiana coast.

Isaac's rainfall will continue to pose a threat during the next few days, with 7 to 14 inches of rain possible over the New Orleans area, with some locations seeing 20 inches.